No Cowboys & Aliens for Robert Downey Jr.

The Los Angeles Times says that Robert Downey Jr. won’t be reteaming with his “Iron Man” franchise director Jon Favreau for Cowboys & Aliens, DreamWorks’ adaptation of the graphic novel. Alex Kurtzman, Roberto Orci and Damon Lindelof wrote the script.

Favreau will still direct, but Downey Jr. had to drop out due to scheduling conflicts. Production is tentatively set to begin this year for a planned release in summer 2011.

The sci-fi Western explores what would happen if the traditional Old West enemies — cowboys and Native Americans — found the prairie attacked by aliens in mid-1800s Arizona.